LT3579/LT3579-1
TYPICAL APPLICATION
1MHz SEPIC Converter Generates a 12V Output from
a 9V to 16V Input
VPWR
9V TO 16V
VIN
3.3V TO VPWR
L1
• 6.8μH
C1
4.7μF
D1
CPWR
4.7μF
SW1 SW2
VIN
FB
L2
6.8μH
•
SHDN
GATE
100k
LT3579
FAULT CLKOUT
CVIN
4.7μF
RT
VC
SYNC GND SS
47pF
86.6k
0.22μF
130k
VOUT
12V
1.9A*
COUT
10μF
s3
9.53k
2.2nF
3579 TA29
CPWR: 4.7μF, 25V, X7R, 1206
CVIN: 4.7μF, 25V, X7R, 1206
C1: 4.7μF, 25V, X7R, 1206
*MAX OUTPUT CURRENT
VPWR = 9V
COUT: 10μF, 25V, X7R, 1210
VIN = 3.3V TO 5V 1.6A
D1: DIODES INC MBRM360
L1, L2: COOPER BUSSMANN DRQ125-6R8-R VIN = VPWR
1.4A
VPWR = 12V
1.9A
1.4A
LINE REGULATION (VIN = 5V, IOUT = 1A) = 0.017%/V
LOAD REGULATION (VPWR = 12V, VIN = 5V) = –0.23%/A
Efficiency and Power Loss
100
3.2
90
2.8
80
2.4
70
2
60
1.6
VPWR = 12V
50
VIN = 5V
1.2
40
0.8
30
0.4
20
0
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2
LOAD CURRENT (A)
3579 TA08
RELATED PARTS
PART NUMBER
LT3581
LT3580
LT3479
DESCRIPTION
3.3A (ISW), 42V, 2.5MHz, High Efficiency
Step-Up DC/DC Converter
2A (ISW), 42V, 2.5MHz, High Efficiency Step-Up
DC/DC Converter
3A (ISW), 40V, 3.5MHz, High Efficiency Step-Up
DC/DC Converter
COMMENTS
VIN: 2.5V to 22V, VOUT(MAX) = 42V, IQ = 1.9mA, ISD = < 1μA, 4mm × 3mm DFN-14,
MSOP-16E
VIN: 2.5V to 32V, VOUT(MAX) = 42V, IQ = 1mA, ISD = < 1μA, 3mm × 3mm DFN-8,
MSOP-8E
VIN: 2.5V to 24V, VOUT(MAX) = 40V, IQ = 5mA, ISD = < 1μA, 4mm × 3mm DFN-14,
TSSOP-16E
40 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
35791f
LT 0410 • PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 2010